1. Field of the Invention
This invention relates to olefin sulfonate compositions which have useful detergent properties and to the preparation of novel "high-active" compositions useful for preparing them. In greater particularity, the invention relates to concentrated olefin sulfonate (water soluble sulfonic acid salts) compositions, to a novel process for producing them and to anti-gel and "bodied" liquid detergent compositions containing mixtures of sulfonic acid salts and carboxylic acid salts.
2. Description of the Prior Art
The prior art production of detergents using olefin sulfonates (AOS) has been faced with numerous difficulties largely because of the limited water solubility of the olefin sulfonates and because of viscosity problems and gelling tendencies with liquid detergent concentrates containing them. Aqueous solutions of olefin sulfonates are quite thick when the salt concentration is 30-40 percent (weight) or greater and such solutions have a tendency to form gels on standing so that bulk handling of such concentrated solutions is difficult if not impossible. If one uses less concentrated solutins to reduce the handling problems, then the increased water content makes shipping costs per pound of contained sulfonate so expensive as to limit severely the size of the geographical area that can be supplied by an individual sulfonation plant making it necessary to have a plurality of small sulfonation facilities in numerous geographical locations rather than one large plant to serve a large geographical area. This is obviously disadvantageous in numerous ways leading to higher prices. On the other hand, where one desires detergent formulations in which the AOS concentrate is used as a component, the water present in such AOS limits the amount of AOS that can be incorporated into the liquid detergent formulation. In addition, where the AOS concentrate is to be used in "dry" detergent products, minimizing the water content of the AOS concentrate reduces spray drying costs.
Olefin sulfonates useful for detergent purposes are described in detail in the prior art. Compositions are disclosed in U.S. Pat. No. 3,332,880 as consisting of a mixture of three principla components containing from about 10 to about 24 carbon atoms; viz, alkene sulfonic acid salts, hydroxy alkyl sulfonic acid salts and disulfonic acid salts in weight proportions of from about 30 to about 70 percent, from about 20 to about 70 percent, and from about 2 to about 15 percent, respectively. As described in the aforementioned patent, such salt compositions can be produced in various ways. A preferred process for producing olefin sulfonates involves the sulfonation of olefins followed by saponification of the sulfonation product with an appropriate base. The chemical reactions of the saponification step require the combination of an oil phase and a water phase to produce a water phase organic salt system having adequate water present to produce a liquid system within the limits imposed by the solubility of the organic salts present. Thus the prior art saponification operation itself usually is limited by the solubility of the olefin sulfonates. As a practical matter, one generally adjusts the amount of water used in prior art hydrolysis to provide a sulfonate product containing about 30-40 wt. percent salt and 60-70 wt. percent water. This product usually is combined subsequently with various conventional detergent additives such as amides, amine oxides and ethoxy sulfates as described in U.S. Pat. application Ser. No. 201,197, filed Nov. 22, 1971, the text of which is herein incorporated by reference.
In contrast to the gelling problem encountered with the sulfonate detergent compositions that contain from about 25 to about 40 percent olefin sulfonate and described in Ser. No. 201,197, less-concentrated detergent compositions which contain from about 5 to about 25 percent olefin sulfonate have an entirely different problem. These compositions frequently lack "body", appearing undesirably thin or watery. This aspect is discussed in U.S. Pat. No. 3,741,915. In regard to "pumpable" "high active" super concentrates of olefin sulfonates which have about 50 percent water or less, this appears to be an art area that has seen little or no attention in the patent literature.